JPH0478300A - Selection control system for hdlc type remote supervisory controller - Google Patents

Abstract

PURPOSE:To prevent runaway of a gate due to a transmission error, to apply detailed control of almost the same level as that of a conventional system by devising the gate to be activated only at command input. CONSTITUTION:Suppose that the selection control has two behaviors of gate UP or gate DOWN and a time of 1.2sec slightly larger than an HDLC signal period t1=1sec is preset to a fixed timer as a prescribed time. When a transmission error takes place on the way of consecutive transmission of an ON signal, since a succeeding ON signal does not comes to a slave station even lapse of 1.2sec after the reception of the normal ON signal, the slave station stops the UP output automatically and the gate is stopped and no runaway takes place. Since the fault is not clear to the slave station so long as the slave station does not communicate the master station, the section is not released. It is when the fault is made clear that the transmission of telemeter for a prescribed period is failed for the specified number of times. Moreover, the master station detects the fault when the HDLC reception timer counts the prescribed number of times and it is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a selective control method for a remote monitoring and control device for operating a dam gate, etc., and particularly to a selective control method suitable for an HDLC type.

B1 Overview of the Invention The present invention provides a two-behavior selection control method for a remote monitoring and control device that operates a dam gate, etc., in which a fixed timer is set in advance for a predetermined time, and the output of a control command is an on signal and a control for less than the predetermined time. If the side that does not receive the off signal transmits an off signal and outputs a command in response to the received signal, it turns off the command output after the predetermined time, and if the same control command is received within the predetermined time. By re-outputting the command for a predetermined period of time, this system prevents the gate from running out of control due to transmission errors and provides the best technology for an HDLC-type remote monitoring and control device that performs fine-grained control.

C9 Conventional technology Remote monitoring and control devices that operate dam gates, etc. usually use HDLC (High-1 level C) to send and receive commands.
Data Link Control) type protocol is used.

Selection control of the HDLC type remote monitoring and control device is a two-behavior control; first, a selection signal is output from the master station to the slave station, and the slave station returns selection OK to the master station to complete the selection. “In”
, “off”, “stop”, etc., are only possible while this selection is completed.

FIG. 3 is a schematic diagram showing an example of a selection control sequence. As shown in the figure, OK is applied to selection signal nPo5.
After that, once the control signal is output from the master station, the slave station outputs the control signal for a predetermined time (tl, for example, 1 second) to, for example, a dam gate. If there is a change in the control situation, the slave station sends a responsive display status change signal to the master station, and the master station issues a selection normal signal to cancel the selection. When the slave station returns a selection completion return signal, the master station also returns to its normal state.

D9 Problems to be solved by the invention However, the above conventional method has the following problems.

FIG. 4 is a schematic diagram when controlling a dam gate, etc. using a conventional method. In the same figure, during selection, the master station first outputs a raised (or lowered) "in" (or "off") signal to the slave station, and the slave station outputs a raised (or lowered) signal to the external gate at t1. Output time.

The external gate continues to raise (or lower) for 11 hours and sends its position to the master station using a telemeter. When the operator determines that the target position has been reached, the master station sends a gate stop control signal to the slave station. The slave station sends a stop signal to the gate at t1.
Outputs the time and stops the gate in operation. That is, the gate is controlled by a raising (or lowering) operation command and a stop command.

However, when controlling such a gate, etc., when the slave station receives a signal to raise (or lower) once and continues this operation, it is determined that the target position has been reached, and the gate stop control signal is sent from the master station. If a situation occurs in which the slave station is unable to receive the gate stop control signal due to a transmission error even though the gate stop control signal has been transmitted, the maximum time required to detect the transmission error in the HDLC method is the condition that the reception timer fails n times. Therefore, the gate will not stop immediately and the gate will run out of control. For example, if a dam gate opens wider than desired, the amount of water released will be large, and the impact downstream will be immeasurable.

Therefore, this is not a problem that can be dismissed as a simple transmission error.

The present invention was created in view of these problems, and
The object of the present invention is to provide a selective control method for an HDLC remote monitoring and control device that can prevent gates from running out of control due to transmission errors, perform fine-grained control, and provide detailed control at almost the same level as conventional methods.

Means for Solving the E0 Problem The means for solving the above problem in the present invention is a two-behavior selection control method for a remote monitoring and control device using a communication method in which the time required to detect a transmission error is limited by a reception timer. A fixed timer is set in advance for a predetermined time, and the output of the control command is an on signal, and an off signal is sent if the control lasts less than the predetermined time, and the side that outputs the command in response to the received signal does not receive the off signal. In this case, the command output is turned off after the predetermined time, and if the same control command is received within the predetermined time, the command output is performed again for the predetermined time.

F1 action In the current selection control system, a control command is sent from the master station to the slave station, and the gate side that receives this command latches and continues operation until the next stop command arrives.However, in the present invention, the gate side Change the side so that it operates only when a command is input. Stop command is not used.

Control commands from the master station are transmitted not only at the time of issuance, but also after they are issued, as necessary. A predetermined time is set in the fixed timer in advance, and only the ON signal of the control command is transmitted to the slave station, and for control commands that are shorter than the predetermined time, an OFF signal is transmitted within a predetermined time after transmitting the ON signal.

It is assumed that the slave station outputs a command corresponding to reception of both an on signal and an off signal. When an off signal is received, the command output is turned off and the command is issued for less than a predetermined time. If the off signal is not received, the command output is turned off after the predetermined time has elapsed.

Thereby, the gate is stopped by either the off signal or the elapse of a predetermined period of time without using a stop command. If the same control command is received within a predetermined time, the command output with the same time setting is performed again, so the command output is continued.

G. Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 are schematic diagrams showing operations when an HDLC transmission error occurs during gate control in an embodiment in which the selection control method of the present invention is applied to a dam gate. In the figure, the selection control is performed to raise or lower the dam gate, and the fixed timer is preset to 1.2 seconds, which is slightly larger than the HDLC signal period t i =i seconds. Therefore, the control command is 1 after outputting the on signal.
The same signal continues to be sent every second, and is repeated within 1.2 seconds. The operator only has to monitor the position of the gate and send an off signal at a desired time. On the gate side,
It should not be a latch type, but should operate only during signal input.

FIG. 1 is a schematic diagram in which signal transmission and reception are disabled in a normal state. In the figure, the master station of the remote monitoring and control device first sends a selection signal to the slave station, and when the slave station returns a signal indicating that selection is OK, it transmits, for example, an up signal to indicate selection completion. When the slave station receives this ON signal, it operates a fixed timer and outputs a raised output to the gate for 1.2 seconds.

However, after 1 second, the on signal will be received again.
Both the increased output and the fixed timer will be updated.

The gate side continues to raise while the ON signal continues. As described above, the operator monitors the position of the gate and sends an off signal at a desired time, causing the gate to stop raising. The master station transmits a selection normal signal, and the slave station cancels the selection and returns a selection completion return signal to return to normal operation.

FIG. 2 is a schematic diagram showing signal transmission and reception when a transmission error occurs. In the same figure, if a transmission error occurs while the ON signal is being sent in the same way as in Figure 1, the slave station will not receive the next signal even after 1.2 seconds have passed after receiving the normal ON signal. Since the ON signal is not received, the output is automatically raised and the gate is stopped, preventing the gate from running out of control.

However, since the slave station will not be found to be abnormal unless it communicates with the master station, it will not be deselected. An abnormality is discovered when the transmission of fixed-period telemeters fails a specified number of times. Further, when the HDLC reception timer counts a predetermined number of times, the master station detects an abnormality and closes the service.

This example clearly has the following effects.

(1) Eliminate gate runaway due to transmission errors during gate control.

(2) - Fine layer control becomes possible and control output within 1 second is achieved.

(3) Circuit breakers, LS, pumps, etc. can be controlled at the same level as before.

(4,) It is the best control method for HDLC remote monitoring and control equipment.

Effects of the H8 Invention As explained above, according to the present invention, gate runaway due to transmission errors is prevented, detailed control is performed, the detailed control is at almost the same level as conventional methods, and HDLC type remote monitoring control is achieved. The device can provide the best selection control method.

[Brief explanation of drawings]

1 and 2 are schematic diagrams of an embodiment of the present invention, FIG. 3 is a schematic diagram of a selection control system, and FIG. 4 is a schematic diagram of a conventional example. Schematic diagram of the normal state of the present invention Normal Schematic diagram of the abnormal state of the present invention Close Kokushi Figure 3 Selection control method

Claims (1)

[Claims] (1) In a two-behavior selection control method for a remote monitoring and control device using a communication method in which the time required to detect a transmission error is limited by a reception timer, a fixed timer is set in advance for a predetermined time, and the control command output is an ON signal and In the case of control for less than a predetermined time, an off signal is transmitted, and if the off signal is not received on the side that outputs a command in response to the received signal, the command output is turned off after the predetermined time, and the same control is performed within the predetermined time. An HDL characterized in that when a command is received, the command is output again for a predetermined period of time.
Selective control method for C-type remote monitoring and control equipment.